Commit graph

73 commits

Author SHA1 Message Date
Andrew Morton
5b149bcc23 [PATCH] schedule_timeout(): improve warning message
Kyle is hitting this warning, and we don't have a clue what it's caused by.
Add the obligatory dump_stack().

Cc: kyle <kylewong@southa.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 08:55:49 -08:00
Eric Dumazet
cd7175edf9 [PATCH] Optimize calc_load()
calc_load() is called by timer interrupt to update avenrun[].  It currently
calls nr_active() at each timer tick (HZ per second), while the update of
avenrun[] is done only once every 5 seconds.  (LOAD_FREQ=5 Hz)

nr_active() is quite expensive on SMP machines, since it has to sum up
nr_running and nr_uninterruptible of all online CPUS, bringing foreign
dirty cache lines.

This patch is an optimization of calc_load() so that nr_active() is called
only if we need it.

The use of unlikely() is welcome since the condition is true only once every
5*HZ time.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13 09:05:55 -08:00
Daniel Walker
f5f1a24a2c [PATCH] clocksource: small cleanup
Mostly changing alignment.  Just some general cleanup.

[akpm@osdl.org: build fix]
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:22 -08:00
Arjan van de Ven
4c36a5dec2 [PATCH] round_jiffies infrastructure
Introduce a round_jiffies() function as well as a round_jiffies_relative()
function.  These functions round a jiffies value to the next whole second.
The primary purpose of this rounding is to cause all "we don't care exactly
when" timers to happen at the same jiffy.

This avoids multiple timers firing within the second for no real reason;
with dynamic ticks these extra timers cause wakeups from deep sleep CPU
sleep states and thus waste power.

The exact wakeup moment is skewed by the cpu number, to avoid all cpus from
waking up at the exact same time (and hitting the same lock/cachelines
there)

[akpm@osdl.org: fix variable type]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:22 -08:00
Atsushi Nemoto
8ef386092d [PATCH] kill wall_jiffies
With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies.
So we can kill wall_jiffies completely.

This is just a cleanup and logically should not change any real behavior
except for one thing: RTC updating code in (old) ppc and xtensa use a
condition "jiffies - wall_jiffies == 1".  This condition is never met so I
suppose it is just a bug.  I just remove that condition only instead of
kill the whole "if" block.

[heiko.carstens@de.ibm.com: s390 build fix and cleanup]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:27 -07:00
Roman Zippel
8f807f8d21 [PATCH] ntp: add time_adjust to tick length
This folds update_ntp_one_tick() into second_overflow() and adds time_adjust
to the tick length, this makes time_next_adjust unnecessary.  This slightly
changes the adjtime() behaviour, instead of applying it to the next tick, it's
applied to the next second.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:26 -07:00
Roman Zippel
b0ee75561b [PATCH] ntp: add ntp_update_frequency
This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not
performance critical).  ntp_update_frequency() calculates the base tick length
using tick_usec and adds a base adjustment, in case the frequency doesn't
divide evenly by HZ.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:26 -07:00
john stultz
4c7ee8de95 [PATCH] NTP: Move all the NTP related code to ntp.c
Move all the NTP related code to ntp.c

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:26 -07:00
Atsushi Nemoto
3171a0305d [PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem)
Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
timer interrupt handler with this change.

Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
callers of do_timer() should know how many ticks to update.  Passing ticks
get rid of this redundant calculation.  Also there are another redundancy
pointed out by Martin Schwidefsky.

This cleanup make a barrier added by
5aee405c66 needless.  So this patch removes
it.

As a bonus, this cleanup make wall_jiffies can be removed easily, since now
wall_jiffies is always synced with jiffies.  (This patch does not really
remove wall_jiffies.  It would be another cleanup patch)

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:15 -07:00
Akinobu Mita
07dccf3344 [PATCH] check return value of cpu_callback
Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu()
may fail with small memory.  If it happens in initcalls, kernel NULL
pointer dereference happens later.  This patch makes crash happen
immediately in such cases.  It seems a bit better than getting kernel NULL
pointer dereference later.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:14 -07:00
Rolf Eike Beer
2aae4a108d [PATCH] Fix kerneldoc comments in kernel/timer.c
Some of the kerneldoc comments in this file are ignored since the lead-in
is malformed, using either "/*" or "/***" instead of "/**".

[rdunlap@xenotime.net: kerneldoc fixes]
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:10 -07:00
Josh Triplett
89e7e374dd [PATCH] timer: add lock annotation to lock_timer_base
lock_timer_base acquires a lock and returns with that lock held.  Add a
lock annotation to this function so that sparse can check callers for lock
pairing, and so that sparse will not complain about this function since it
intentionally uses the lock in this manner.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:09 -07:00
Kirill Korotaev
6997a6faaa [PATCH] sys_getppid oopses on debug kernel
sys_getppid() optimization can access a freed memory.  On kernels with
DEBUG_SLAB turned ON, this results in Oops.  As Dave Hansen noted, this
optimization is also unsafe for memory hotplug.

So this patch always takes the lock to be safe.

[oleg@tv-sign.ru: simplifications]
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: <stable@kernel.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:29 -07:00
Josh Triplett
51d8c5edd3 [PATCH] timer: Fix tvec_bases initializer
kernel/timer.c defines a (per-cpu) pointer to tvec_base_t, but initializes
it using { &a_tvec_base_t }, which sparse warns about; change this to just
&a_tvec_base_t.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:44 -07:00
Steven Rostedt
6ea24f9ad1 [PATCH] fix bad macro param in timer.c
We have

#define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK

and it's used via

	list = varray[i + 1]->vec + (INDEX(i + 1));

So, due to underparenthesisation, this INDEX(i+1) is now a ...  (TVR_BITS + i
+ 1 * TVN_BITS)) ...

So this bugfix changes behaviour.  It worked before by sheer luck:

  "If i was anything but 0, it was broken.  But this was only used by
   s390 and arm.  Since it was for the next interrupt, could that next
   interrupt be a problem (going into the second cascade)? But it was
   probably seldom wrong.  That is, this would fail if the next
   interrupt was in the second cascade, and was wrapped.  Which may
   never of happened.  Also if it did happen, it would have just missed
   the interrupt.

   If an interrupt was missed, and no one was there to miss it, was it
   really missed :-)"

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:40 -07:00
Chandra Seetharaman
8c78f3075d [PATCH] cpu hotplug: replace __devinit* with __cpuinit* for cpu notifications
Few of the callback functions and notifier blocks that are associated with cpu
notifications incorrectly have __devinit and __devinitdata.  They should be
__cpuinit and __cpuinitdata instead.

It makes no functional difference but wastes text area when CONFIG_HOTPLUG is
enabled and CONFIG_HOTPLUG_CPU is not.

This patch fixes all those instances.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:39 -07:00
john stultz
3e143475c2 [PATCH] improve timekeeping resume robustness
Resolve problems seen w/ APM suspend.

Due to resume initialization ordering, its possible we could get a timer
interrupt before the timekeeping resume() function is called.  This patch
ensures we don't do any timekeeping accounting before we're fully resumed.

(akpm: fixes the machine-freezes-on-APM-resume bug)

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 21:53:54 -07:00
Andrew Morton
a0009652af [PATCH] del_timer_sync(): add cpu_relax()
Relax the CPU in the del_timer_sync() busywait loop.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 21:53:52 -07:00
Roman Zippel
e154ff3d2c [PATCH] adjust clock for lost ticks
A large number of lost ticks can cause an overadjustment of the clock.  To
compensate for this we look at the current error and the larger the error
already is the more careful we are at adjusting the error.  As small extra
fix reset the error when the clock is set.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Acked-by: john stultz <johnstul@us.ibm.com>
Cc: Uwe Bugla <uwe.bugla@gmx.de>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:18 -07:00
Ingo Molnar
36c8b58689 [PATCH] sched: cleanup, remove task_t, convert to struct task_struct
cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:11 -07:00
Ingo Molnar
d730e882a1 [PATCH] lockdep: annotate timer base locks
Split the per-CPU timer base locks up into separate lock classes, because they
are used recursively.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:07 -07:00
Ingo Molnar
e4d9191885 [PATCH] lockdep: locking init debugging improvement
Locking init improvement:

 - introduce and use __SPIN_LOCK_UNLOCKED for array initializations,
   to pass in the name string of locks, used by debugging

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:02 -07:00
Chandra Seetharaman
054cc8a2d8 [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17
This patch reverts notifier_block changes made in 2.6.17

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:41 -07:00
Chandra Seetharaman
9c7b216d23 [PATCH] cpu hotplug: revert init patch submitted for 2.6.17
In 2.6.17, there was a problem with cpu_notifiers and XFS.  I provided a
band-aid solution to solve that problem.  In the process, i undid all the
changes you both were making to ensure that these notifiers were available
only at init time (unless CONFIG_HOTPLUG_CPU is defined).

We deferred the real fix to 2.6.18.  Here is a set of patches that fixes the
XFS problem cleanly and makes the cpu notifiers available only at init time
(unless CONFIG_HOTPLUG_CPU is defined).

If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run
time.

This patch reverts the notifier_call changes made in 2.6.17

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:40 -07:00
Roman Zippel
19923c190e [PATCH] fix and optimize clock source update
This fixes the clock source updates in update_wall_time() to correctly
track the time coming in via current_tick_length().  Optimize the fast
paths to be as short as possible to keep the overhead low.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:21 -07:00
john stultz
a275254975 [PATCH] time: rename clocksource functions
As suggested by Roman Zippel, change clocksource functions to use
clocksource_xyz rather then xyz_clocksource to avoid polluting the
namespace.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:21 -07:00
john stultz
cf3c769b4b [PATCH] Time: Introduce arch generic time accessors
Introduces clocksource switching code and the arch generic time accessor
functions that use the clocksource infrastructure.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:20 -07:00
john stultz
5eb6d20533 [PATCH] Time: Use clocksource abstraction for NTP adjustments
Instead of incrementing xtime by tick_nsec + ntp adjustments, use the
clocksource abstraction to increment and scale time.  Using the clocksource
abstraction allows other clocksources to be used consistently in the face of
late or lost ticks, while preserving the existing behavior via the jiffies
clocksource.

This removes the need to keep time_phase adjustments as we just use the
current_tick_length() function as the NTP interface and accumulate time using
shifted nanoseconds.

The basics of this design was by Roman Zippel, however it is my own
interpretation and implementation, so the credit should go to him and the
blame to me.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:20 -07:00
john stultz
260a42309b [PATCH] Time: Let user request precision from current_tick_length()
Change the current_tick_length() function so it takes an argument which
specifies how much precision to return in shifted nanoseconds.  This provides
a simple way to convert between NTPs internal nanoseconds shifted by
(SHIFT_SCALE - 10) to other shifted nanosecond units that are used by the
clocksource abstraction.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:20 -07:00
john stultz
ad596171ed [PATCH] Time: Use clocksource infrastructure for update_wall_time
Modify the update_wall_time function so it increments time using the
clocksource abstraction instead of jiffies.  Since the only clocksource driver
currently provided is the jiffies clocksource, this should result in no
functional change.  Additionally, a timekeeping_init and timekeeping_resume
function has been added to initialize and maintain some of the new timekeping
state.

[hirofumi@mail.parknet.co.jp: fixlet]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:20 -07:00
Paul Mackerras
bfe5d83419 [PATCH] Define __raw_get_cpu_var and use it
There are several instances of per_cpu(foo, raw_smp_processor_id()), which
is semantically equivalent to __get_cpu_var(foo) but without the warning
that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled.  For
those architectures with optimized per-cpu implementations, namely ia64,
powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower
code than __get_cpu_var(), so it would be preferable to use __get_cpu_var
on those platforms.

This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x,
raw_smp_processor_id()) on architectures that use the generic per-cpu
implementation, and turns into __get_cpu_var(x) on the architectures that
have an optimized per-cpu implementation.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:01 -07:00
Porpoise
3439dd86e3 [PATCH] When CONFIG_BASE_SMALL=1, cascade() may enter an infinite loop
When CONFIG_BASE_SAMLL=1, cascade() in may enter the infinite loop.
Because of CONFIG_BASE_SMALL=1(TVR_BITS=6 and TVN_BITS=4), the list
base->tv5 may cascade into base->tv5.  So, the kernel enters the infinite
loop in the function cascade().

I created a test module to verify this bug, and a patch to fix it.

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#if 0
#include <linux/kdb.h>
#else
#define kdb_printf printk
#endif

#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
#define TVN_SIZE (1 << TVN_BITS)
#define TVR_SIZE (1 << TVR_BITS)
#define TVN_MASK (TVN_SIZE - 1)
#define TVR_MASK (TVR_SIZE - 1)

#define TV_SIZE(N)  (N*TVN_BITS  + TVR_BITS)

struct timer_list timer0;
struct timer_list dummy_timer1;
struct timer_list dummy_timer2;

void dummy_timer_fun(unsigned long data) {
}
unsigned long j=0;
void check_timer_base(unsigned long data)
{
        kdb_printf("check_timer_base %08x\n",jiffies);
        mod_timer(&timer0,(jiffies & (~0xFFF)) + 0x1FFF);
}

int init_module(void)
{
        init_timer(&timer0);
        timer0.data = (unsigned long)0;
        timer0.function = check_timer_base;
        mod_timer(&timer0,jiffies+1);

        init_timer(&dummy_timer1);
        dummy_timer1.data = (unsigned long)0;
        dummy_timer1.function = dummy_timer_fun;

        init_timer(&dummy_timer2);
        dummy_timer2.data = (unsigned long)0;
        dummy_timer2.function = dummy_timer_fun;

        j=jiffies;
        j&=(~((1<<TV_SIZE(3))-1));
        j+=(1<<TV_SIZE(3));
        j+=(1<<TV_SIZE(4));

        kdb_printf("mod_timer %08x\n",j);

        mod_timer(&dummy_timer1, j );
        mod_timer(&dummy_timer2, j );

        return 0;
}

void cleanup_module()
{
        del_timer_sync(&timer0);
        del_timer_sync(&dummy_timer1);
        del_timer_sync(&dummy_timer2);
}

(Cleanups from Oleg)

[oleg@tv-sign.ru: use list_replace_init()]
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:08 -07:00
Oleg Nesterov
626ab0e69d [PATCH] list: use list_replace_init() instead of list_splice_init()
list_splice_init(list, head) does unneeded job if it is known that
list_empty(head) == 1.  We can use list_replace_init() instead.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:07 -07:00
Zachary Amsden
0662b71322 [PATCH] Fix a NO_IDLE_HZ timer bug
Under certain timing conditions, a race during boot occurs where timer
ticks are being processed on remote CPUs.  The remote timer ticks can
increment jiffies, and if this happens during a window when a timeout is
very close to expiring but a local tick has not yet been delivered, you can
end up with

1) No softirq pending
2) A local timer wheel which is not synced to jiffies
3) No high resolution timer active
4) A local timer which is supposed to fire before the current jiffies value.

In this circumstance, the comparison in next_timer_interrupt overflows,
because the base of the comparison for high resolution timers is jiffies,
but for the softirq timer wheel, it is relative the the current base of the
wheel (jiffies_base).

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:21 -07:00
Chandra Seetharaman
83d722f7e1 [PATCH] Remove __devinit and __cpuinit from notifier_call definitions
Few of the notifier_chain_register() callers use __init in the definition
of notifier_call.  It is incorrect as the function definition should be
available after the initializations (they do not unregister them during
initializations).

This patch fixes all such usages to _not_ have the notifier_call __init
section.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26 08:30:03 -07:00
Chandra Seetharaman
649bbaa484 [PATCH] Remove __devinitdata from notifier block definitions
Few of the notifier_chain_register() callers use __devinitdata in the
definition of notifier_block data structure.  It is incorrect as the
data structure should be available after the initializations (they do
not unregister them during initializations).

This was leading to an oops when notifier_chain_register() call is
invoked for those callback chains after initialization.

This patch fixes all such usages to _not_ have the notifier_block data
structure in the init data section.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26 08:27:50 -07:00
Andrew Morton
ba6edfcd17 [PATCH] timer initialisation fix
We need the boot CPU's tvec_bases[] entry to be initialised super-early in
boot, for early_serial_setup().  That runs within setup_arch(), before even
per-cpu areas are initialised.

The patch changes tvec_bases to use compile-time initialisation, and adds a
separate array `tvec_base_done' to keep track of which CPU has had its
tvec_bases[] entry initialised (because we can no longer use the zeroness of
that tvec_bases[] entry to determine whether it has been initialised).

Thanks to Eugene Surovegin <ebs@ebshome.net> for diagnosing this.

Cc: Eugene Surovegin <ebs@ebshome.net>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:40 -07:00
Jordan Hargrave
b20367a6c2 [PATCH] x86_64: Fix drift with HPET timer enabled
If the HPET timer is enabled, the clock can drift by ~3 seconds a day.
This is due to the HPET timer not being initialized with the correct
setting (still using PIT count).

If HZ changes, this drift can become even more pronounced.

HPET patch initializes tick_nsec with correct tick_nsec settings for
HPET timer.

Vojtech comments:

  "It's not entirely correct (it assumes the HPET ticks totally
   exactly), but it's significantly better than assuming the PIT error
   there."

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-09 11:53:53 -07:00
Eric Sesterhenn
9f31252cb6 BUG_ON() Conversion in kernel/signal.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-02 13:45:55 +02:00
Jack Steiner
db1b1fefc2 [PATCH] sched: reduce overhead of calc_load
Currently, count_active_tasks() calls both nr_running() &
nr_interruptible().  Each of these functions does a "for_each_cpu" & reads
values from the runqueue of each cpu.  Although this is not a lot of
instructions, each runqueue may be located on different node.  Depending on
the architecture, a unique TLB entry may be required to access each
runqueue.

Since there may be more runqueues than cpu TLB entries, a scan of all
runqueues can trash the TLB.  Each memory reference incurs a TLB miss &
refill.

In addition, the runqueue cacheline that contains nr_running &
nr_uninterruptible may be evicted from the cache between the two passes.
This causes unnecessary cache misses.

Combining nr_running() & nr_interruptible() into a single function
substantially reduces the TLB & cache misses on large systems.  This should
have no measureable effect on smaller systems.

On a 128p IA64 system running a memory stress workload, the new function
reduced the overhead of calc_load() from 605 usec/call to 324 usec/call.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:58 -08:00
Oleg Nesterov
a2c348fe01 [PATCH] __mod_timer: simplify ->base changing
Since base and new_base are of the same type now, we can save one 'if'
branch and simplify the code a bit.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:53 -08:00
Oleg Nesterov
3691c5199e [PATCH] kill __init_timer_base in favor of boot_tvec_bases
Commit a4a6198b80:
	[PATCH] tvec_bases too large for per-cpu data

introduced "struct tvec_t_base_s boot_tvec_bases" which is visible at
compile time.  This means we can kill __init_timer_base and move
timer_base_s's content into tvec_t_base_s.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:52 -08:00
Roman Zippel
5ddcfa878d [PATCH] remove pps support
This removes the support for pps.  It's completely unused within the kernel
and is basically in the way for further cleanups.  It should be easier to
readd proper support for it after the rest has been converted to NTP4
(where the pps mechanisms are quite different from NTP3 anyway).

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Adrian Bunk <bunk@stusta.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:23:02 -08:00
Thomas Gleixner
c08b8a4910 [PATCH] sys_alarm() unsigned signed conversion fixup
alarm() calls the kernel with an unsigend int timeout in seconds.  The
value is stored in the tv_sec field of a struct timeval to setup the
itimer.  The tv_sec field of struct timeval is of type long, which causes
the tv_sec value to be negative on 32 bit machines if seconds > INT_MAX.

Before the hrtimer merge (pre 2.6.16) such a negative value was converted
to the maximum jiffies timeout by the timeval_to_jiffies conversion.  It's
not clear whether this was intended or just happened to be done by the
timeval_to_jiffies code.

hrtimers expect a timeval in canonical form and treat a negative timeout as
already expired.  This breaks the legitimate usage of alarm() with a
timeout value > INT_MAX seconds.

For 32 bit machines it is therefor necessary to limit the internal seconds
value to avoid API breakage.  Instead of doing this in all implementations
of sys_alarm the duplicated sys_alarm code is moved into a common function
in itimer.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:48 -08:00
Ingo Molnar
6687a97d40 [PATCH] timer-irq-driven soft-watchdog, cleanups
Make the softlockup detector purely timer-interrupt driven, removing
softirq-context (timer) dependencies.  This means that if the softlockup
watchdog triggers, it has truly observed a longer than 10 seconds
scheduling delay of a SCHED_FIFO prio 99 task.

(the patch also turns off the softlockup detector during the initial bootup
phase and does small style fixes)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:30 -08:00
Jan Beulich
a4a6198b80 [PATCH] tvec_bases too large for per-cpu data
With internal Xen-enabled kernels we see the kernel's static per-cpu data
area exceed the limit of 32k on x86-64, and even native x86-64 kernels get
fairly close to that limit.  I generally question whether it is reasonable
to have data structures several kb in size allocated as per-cpu data when
the space there is rather limited.

The biggest arch-independent consumer is tvec_bases (over 4k on 32-bit
archs, over 8k on 64-bit ones), which now gets converted to use dynamically
allocated memory instead.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:21 -08:00
Christoph Lameter
67890d7084 [PATCH] time_interpolator: add __read_mostly
The pointer to the current time interpolator and the current list of time
interpolators are typically only changed during bootup.  Adding
__read_mostly takes them away from possibly hot cachelines.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17 07:51:25 -08:00
Atsushi Nemoto
5aee405c66 [PATCH] time: add barrier after updating jiffies_64
Add a compiler barrier so that we don't read jiffies before updating
jiffies_64.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06 18:40:44 -08:00
Tony Lindgren
69239749e1 [PATCH] fix next_timer_interrupt() for hrtimer
Also from Thomas Gleixner <tglx@linutronix.de>

Function next_timer_interrupt() got broken with a recent patch
6ba1b91213 as sys_nanosleep() was moved to
hrtimer.  This broke things as next_timer_interrupt() did not check hrtimer
tree for next event.

Function next_timer_interrupt() is needed with dyntick (CONFIG_NO_IDLE_HZ,
VST) implementations, as the system can be in idle when next hrtimer event
was supposed to happen.  At least ARM and S390 currently use
next_timer_interrupt().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06 18:40:44 -08:00
Christoph Lameter
685db65e42 [PATCH] time_interpolator: Use readq_relaxed() instead of readq().
On some platforms readq performs additional work to make sure I/O is done
in a coherent way.  This is not needed for time retrieval as done by the
time interpolator.  So we can use readq_relaxed instead which will improve
performance.

It affects sparc64 and ia64 only.  Apparently it makes a significant
difference on ia64.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-02 08:33:07 -08:00